System of electrical distribution.



110. 773917. PATENTED NOV. 1,1904. W. L. BLISS.

SYSTEM OF ELECTRICAL DISTRIBUTION.

APPLICATION FILED FEB.3. 1902.

N0 MODEL.

Patented November 1, 1904.

UNITED STATES PATENT OFFICE.

WILLIAM LORD BLISS, OF BROOKLYN, NEW YORK, ASSIGNOR TO BLISS ELECTRICOAR LIGHTING COMPANY, OF NEW YORK, N. Y., A CORPO- RATION OF NEW JERSEY.

SYSTEM OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of Letters Patent No. 773,917, dated November1, 1904. Application filed February 3, 1902- Serial No. 92,407; (Nomodel.)

To all whom, it may concern:

Be it known that I, WILLIAM LORD BLIss, a citizen of the United States,and a resident of the borough of Brooklyn,in the city and State 5 of NewYork, have inventeda new and useful System of'Electrical Distribution,of which the following is a specification.

The object of my invention is to provide a system of electricaldistribution comprisinga IO primary generator, areceivingcircuit---such, for instance, as a storage batteryand meansunder the control of the receiving-circuit for automatically reducingthe charging effect of the generator when the circuit is charged to I 5a predetermined point, the said means being also under the control ofthe operation of the generator for automatically restoringthe generatorto its normal operative electrical condition.

2O The system is particularly useful wherein translating devices aresupplied with electrical energy by means of a storage battery and aworking circuit connected with a dynamoelectric machine or generatorwhose function 5 is to supply the said working circuit with electricalenergy and also to charge the said storage battery. Systems of thisnature are found especially in the electric lighting of railway-cars,wherein a dynamo driven from 3 the car-axle furnishes the electricalenergy for operating the translating devices and for charging thestorage battery, which in turn supplies the electrical energy necessaryto operate the said translating devices whenever 3 for any reason thedynamo is unable to do so.

In systems of this character it is usual to provide an automatic switchfor closing the circuit between the dynamo and storage battery when itis desired to charge the battery,

4 which switch will open the said circuit when otherwise the storagebattery would discharge through the dynamo. Such a switch should operatewhen the voltages of the dynamo and battery are approximately equal,closing the circuit for an increasing dynamo voltage and opening thecircuit for a decreasing dynamo voltage. It is therefore desirable thatsuch a switch should be controlled directly bythe dynamo voltage and notby some other quantitysuch, for instance, as speed, field-cur- 5 rent,&c.-which may or may not be functions of the dynamo voltage. A simpleand reliable switch of this characteris set forth in United StatesLetters Patent granted to me the 8th day of December, 1896, No. 572,627.In general, the dynamo voltage is mainly dependent on the dynamo speed,and as this speed in electric-car-lighting work varies from zero tomaximum very frequently the operation of the dynamo is extremely iiiter-6O mittent, and therefore if the translating devices are to be operatedcontinuously or at will the dynamo must, in addition to supplying thetranslating devices with electrical energy while the said dynamo isrunning at 5 sufficient speed to enable it to do so, store electricalenergy in the storage battery to,

supply the translating devices whenever the dynamo runs below anoperative speed or stops entirely. In adjusting the apparatus 7 toprovide for sufficient charging of the battery to meet the requirementsof all kinds of service it frequently happens that the batteries becomeovercharged, which is an undesirable condition, as it results in theexcessive deterioration of the batteries. I have therefore in thisinvention provided a simple and automatic device whereby when thecharging process is continued as long as desirable and the batteries arefully charged the 30 dynamo is rendered to a certain extent inoperativeand ceases to charge the batteries, although it may or may not continueto supply the translating devices.

The accompanying drawing represents a 5 system of electricaldistribution ei'nbodying my invention.

A dynamo is represented conventionally at A, and the mechanical meansfor driving the same by B.. The automatic switch is denoted 9 by O, thestorage battery by D, and the translating devices by E. These severaldevices may be of any Well-known or approved construction.

n represents the armature of the dynamo A; u, the commutator; (1 N thetwo commutator-brushes; a", the field-magnet, and 1/," theenergizing-coil.

The means for driving the dynamo which I have represented herein consistof a ear-wheel 7), having its axle 7/ provided with a pulley 6 aroundwhich passes a driving-belt 7), which also passes around a pulley l) onan intermediate shaft 7f, having a gear 1) connecting with a gear on thed ynamo-armature shaft.

The automatic switch Cconsists of the contact-blocks r: 0, contact-wedgec armature c, lifting-coil a, and releasing-coil 0". The lifting-coil c"is composed of a fine wire of high resistance connected across theterminals or brushes (1 a of the dynamo. The releasingcoil 0 consists ofa few turns of coarse wire and is connected directly in series with thedynamo A and storage battery D. A retractile spring (2 may be providedfor yieldingly holding the armature in its open position.

My improved cut-off device is denoted as a whole by F. The solenoid ofthe cut-off define wire connected across the terminals or brushes a? aof the dynamo A. The solenoid contains a movable core f and a stationarycorey. A bar 7" is attached to but insulated from the movable core f,which bar is provided with contact-pins ff, arranged to engage anddisengage cups of mercury f1 Supplementary contactblocks f f are arranged in position to be electrically connected by the bar f when themovable core f is raised by the energization of the solenoid 7". TVhenthe bar f is in contact with said supplementary contact-blocks f" f, thepins f f are lifted out of electrical contact with the mercury-cups f f.

The dynamo being connected as a self-exciting shunt-machine, the currentfor exciting its field is generated in the armature a and traverses thefollowing circuit: from positive brush a, through wire 1, wire 2, cup fpin 7, bar f, pin f, cup f, wire 3, fieldmagnet coil (5, wire 4, wire 5,to negative brush a".

If the armature (a sufl'er reversal in its direcmake an electricalconnection between the blocks 0 c. A slight increase in the dynamovoltage above the storage-battery voltage will cause the main current totraverse the following circuit: from dyname-commutator a, brush (1through wire 1, wire 6, block 0, wedge 0*, block a, releasing-coil a,wire 7, battery 1),

l i l l l i l 4 wire 8, wire 5, and brush (1 to d ynanw-commu tator (I.The releasing-coil of the switch (1 is so connected that when thecurrent flows from the dynamo to the battery in the direction of thearrow the said coil 0" assists the lifting-coil c and securely holds thewedge of the armature 1 in contact with the blocks 0 c. When the voltageof the dynamo falls below the battery voltage, the current will flowfrom the battery through the dynamo in a direction opposite to thatindicated by the arrow, and in this case the releasing-coil a of theautomatic switchCwilloppose the liftingcoil 0 with sufficient strengthto cause the release of the armature thus breaking the connectionbetween the blocks 0 a. A small reverse-current only is necessary tocause the release of the armature for breaking the circuit.

Let it be assumed that the dynamo A is generating a current and ischarging the storage battery 1), the switch C being closed, and that thecurrent which is flowing through the storage battery is the normalcharging-curren t, as prescribed by the manufacturers of the battery. lncar-lighting systems the normal charging-current is caused to flowthrough the battery when the train is moving at an average runningspeed. After charging the battery for a certain length of time at thenormal rate the voltage at the terminals of the battery or the dynamo isa good indication of the state of the battery, and when said voltage isabout 2.4 volts per cell the battery may be said to be fully charged.The solenoid fol the cut-off F is subjected at all times to the terminalvoltage of the dynamo A and also when the switch 0 is closed to theterminal voltage of the battery I), which is now equal to that of thedynamo, through the wires 9 and 10, and when the said battery voltagehas risen to a value of about 2. 1 volts per cell the core f" of thesolenoid f is drawn upwardly, thus lifting the pins ff out of then'iercury-cups f f". This operation causes the field-circuit of thedynamo to be broken at the pins f" f. This would result in destroyingthe magnetism of the field-magnet a" of the dynamo and would reduce thevoltage of the dynamo to zero were it not for the fact that the bar f,carried by the movable core of the solenoid, makes an electricalconnection between the supplementary contact-blocksf f, thusestablishing a current from the pole of the storage battery 1), throughwire 11, resistance 12, wire 13, blockf' bar f, block f, wire 14, wire3, coil (1", wire 4, and wire 8 t0 the pole of the storage battery 1.).This current energizes i the lield-magnet coil a to any degree desiredand enables the dynamo to produce any desired voltage up to its maximum.

In practice I have found it desirable so to adjust the resistance 12that the dynamo voltage shall be reduced to a little less than thatrequired to close the switch C. Under these conditions the switch 0 willautomatically open in precisely the same manner as heretofore described.

The lifting-coil 0* of the switch C is ordinarily connected to thedynamo-terminals by a wire 15 leading from its end to the wire 6 and awire 16 leading from its end to the wire 10. When the circuit throughthe lifting-coil 0* of the switch Cis broken, the switch C will open,thus breaking the main current flowing through the wire? withoutrequiring thereverse-current to pass therethrough, as in the case wherethe lifting-coil 0 remains energized; As has been stated, the resistance12 is so adjusted that after the operation of the cut-off Fthe voltageof the dynamo would be reduced to a'little less than that required toclose the switch C; but it is great enough to hold the movable core f ofthe solenoid f raised, so as to keep a connection between the blocks f fthrough the bar f If the supplementary contact-block's f had not beenutilized,the dynamo voltage would have fallen to zero every time thefield-circuit was broken at the cut-ofi and the solenoidf would havereleased the movable core f and again reestablished the field-circuit.The dynamo would now excite itself. the switch 0 would close, and thecharging process 'would continue, which is exactly what it is desired toprevent. In fact, this cycle of operations might be re peated over andover again wereit not for the fact that the dynamo was not made whollyinoperative by breaking the field-circuit by the lifting of the pins fand f out of their respective mercury-cups f and f" and the furnishingof a separate and independent field excitation from the battery by thecontact of the bar f and the contacts f and f It might be suggested thatthe supplementary contacts f 7 n be dispensed with and a resistanceconnected between the mercurycupsf and f, which would be normallyshortcircuited by the pins f and f dipping into the mercury in theirrespective cups. When these pins were lifted out of their cups, theresistance mentioned would be thrown into the field-circuit and thedynamo would be rendered inoperative to a certain degree, as before. Theobjection to this arrangement is that the dynamo still acting as aselfexcited machine with a large resistance in its field, which wouldconsequently be very weak,would be in general quite unstable, and thevoltage of the dynamo might with a slight reduction in speed less thanplanned for suddenly van.

ish and prematurely effect the restoration of the cut-off F. Thesupplementary contacts and the switching over from self to separateexcitation is an expedient simply to secure stability.

There are many indirect methodsof rendering the dynamo to a certainextent inoperative; but all require an ultimate reduction sition by anadditional reduction of the vol- 1 tage in the dynamo to a predeterminedpoint. This reduction is obtained by the reduction in the speed withwhich the dynamo is driven by the mechanical means which in theaccompanying drawing I have represented as a car axle. When the trainstops or slows down to a predetermined degree, the voltage in the dynamowill also fall to such a point that the solenoid will no longer be ableto hold the bar f in contact with the blocksf' f. The bar will then falland reestablish the original fieldcircuit. I

The time that the charging process is discontinued is the time thatelapses from the instant that the field-circuit is broken to the instantthat the field-circuit is again reestablished at the cut-off caused bythe reduction in the speed of the mechanical driving means for thedynamo. When this system is used in connection with car-lighting, thetime that the charging is discontinued may be longer or shorter as theconditions vary. If the cutoff is operated shortly after the car hasstarted on a long run'during which there is no such slackening of speedas would cause the restoration of the cut-off, the voltage in thestorage battery would be slowly reduced, the capacity of the batterybeing sufficient to continue the operation of the translating devicesduring the longest run made by the train. The solenoid may be soadjusted that the cut-oif may be restored with a very slight additionalreduction of the dynamo voltage, so that the slowing up of the trainsuchas would occur when the locomotive is taking water from the track tanks,when the train is ascending grades, or when it is passing throughtownswill restore the cut-off, thus preventing the exhaustion of thebatteries during a long run of the train. 7

By adjusting the resistance 12 any degree or period of inactivity can besecured. The dynamo may be rendered inoperative as far as charging thebattery is concerned; but the switchC might still remain closed, wherebythe dynamo could carry any portion of the lamp load desired.Theresistance 12 may also be so adjusted that the dynamo would be causedonly partially to discontinue charging the battery while it stillcarries the lamp load.

What I claim is 1. In a system of electrical distribution, a primarygenerator, means for driving it, a storage battery, means forautomatically reducing the electrical energy which the said generatorsupplies to the said storage battery when the storage battery is fullycharged, and means under the control of the generator-driving mechanism,for restoring the generator to its normal operative condition,substantially as set forth.

2. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, means under the control of thestorage battery t'or automatically reducing the electrical energy whichthe said generator supplies to the said storage battery when thereceiving-circuit is fully charged, and means under the control of thegeneratordriving mechanism for restoring the generator to its normaloperative condition, substantially as set forth.

3. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, means under the control of thestorage battery for automatically reducing the charging effect of thegenerator when the storage battery is fully charged, and means under thecontrol of the generator-driving mechanism for restoring the generatorto its normal operative condition, substantially as set forth. I

at. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, means under the control of thestorage battery for reducing the electrical energy which said generatorsupplies to the said storage battery when the storage battery is chargedto a predetermined point, and means under the control of thegenerator-driving mechanism for restoring the generator to its normaloperative condition, substantially as set forth.

5. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, means under the control of thestorage battery for automatically reducing the charging efl'ect of thegenerator when the storage battery is charged to a predetermined point,and means under the control of the generator-driving mechanism forrestoring the generator to its normal operative condition, when thespeed of the generator-driving mechanism reaches a predetermined point,substantially as set forth.

6. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, means under the control of thestorage battery for automatically reducing the charging of the same bythe generator, when the battery is charged to a predetermined point, andmeans under the control of the generator-driving mechanism for restoringthe generator to its normal operative condition, substantially as setforth.

7. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, a translating device, means under thecontrol of the storage battery for automatically reducing the chargingof the battery by the generator when the battery is charged to apredetermined point, and means under the control of thegenerator-driving mechanism for restoring the generator to its normaloperative condition, substantially as set forth.

8. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, a translating device, means under thecontrol of the storage battery for automatically reducing the chargingof the storage battery by the generator when the battery is charged to apredetermined point, and means also under the control of thegenerator-driving mechanism for restoring the generator to its normaloperative condition, when the speed of the generator driving mechanismreaches a predetermined point, substantially as set forth.

9. in a system of electrical distribution, a primary generator, astorage battery, means under the control of the storage battery forautomatically reducing the charging of the storage battery by thegenerator when the storage battery is charged to a predetermined point,and means under the control of the operation of the generator forautomatic: lly restoring the generator to its normal operativecondition, substantially as set forth.

10. In a system of electrical distribution, a primary generator, astorage battery, means for automatically changing the normal electricalcondition of the primary generator, when the battery is charged to apredetermined point, for requiring a reductionin the supply ofelectrical energy, and means under the control of the operation of theprimary generator for restoring the generator to its normal operativecondition, substantially as set forth.

11. In a system of electrical distribution, a primary generator, meansfor driving it, a storage battery, means under the control of thestorage battery for automatically reducing the charging of the storagebattery by the generator when the storage battery is charged to apredetermined point, and means under the control of the mechanism fordriving the generator whereby the generator will be restored to itsnormal operative electrical condition, whenever the speed of thegeneratordriving mechanism is lowered to a predetermined point,substantially as set forth.

In testimony that 1 claim the foregoing as my invention 1 have signed myname, in presence of two witnesses, this 22d day of January, 1902.

\VILLIAM LORD BLISS.

Vi tnesses:

FREDK. HAYNIJs, C. S. SUNDennN.

IIO

